Sierra467
03-07-2008, 06:31
Hi there,
I live in Maine and I have a 2002 GMC 2500HD Duramax/Allison Tranny. I had been having a problem with my truck for about a week and was forced to take it into the shop. I thought that my story might help someone else so that is why I am posting.
About a week ago I started having trouble with my shift indicator light on the dash (PRNDL - Park Reverse Neutral Drive Low - for those who like me did not know at the time). I would shift into drive and the light designating the gear on the dash would not illuminate Drive. Then the light would trail behind the gear shifted into and also the doors would not unlock when shifted into Park. I thought it possibly might be a cable issue so I looked into the steering column and found nothing.
Then a couple of days ago, I got in the truck and noticed the Service Engine Light was on. I drove on my way to the dealer to get it checked out when I noticed the truck would not shift and I could only go about 25-30mph. I later found out that this was a LIMP mode, a self preservation mode the truck puts itself in to protect itself. I also noticed that when switching gears I was getting a louder than normal clunking when shifting between gears. Not knowing what was going on, I had it towed to the local Dealer.
I was told that the problem was an external module near the Transmission called a PRNDL module or switch that failed (nothing I did, they said, it just has a shelf life and mine was up). It was explained to me, that this module is what determines the gears for the tranny and that it was the cause of all my problems.
I had it repaired and since I had 100,008mi, I had the tranny filter and liquids changed too. This little adventure cost me about 415$ for those who are curious. I supposed it could have been worse but it hurt a bit. The best part is that I am back on the road.
I live in Maine and I have a 2002 GMC 2500HD Duramax/Allison Tranny. I had been having a problem with my truck for about a week and was forced to take it into the shop. I thought that my story might help someone else so that is why I am posting.
About a week ago I started having trouble with my shift indicator light on the dash (PRNDL - Park Reverse Neutral Drive Low - for those who like me did not know at the time). I would shift into drive and the light designating the gear on the dash would not illuminate Drive. Then the light would trail behind the gear shifted into and also the doors would not unlock when shifted into Park. I thought it possibly might be a cable issue so I looked into the steering column and found nothing.
Then a couple of days ago, I got in the truck and noticed the Service Engine Light was on. I drove on my way to the dealer to get it checked out when I noticed the truck would not shift and I could only go about 25-30mph. I later found out that this was a LIMP mode, a self preservation mode the truck puts itself in to protect itself. I also noticed that when switching gears I was getting a louder than normal clunking when shifting between gears. Not knowing what was going on, I had it towed to the local Dealer.
I was told that the problem was an external module near the Transmission called a PRNDL module or switch that failed (nothing I did, they said, it just has a shelf life and mine was up). It was explained to me, that this module is what determines the gears for the tranny and that it was the cause of all my problems.
I had it repaired and since I had 100,008mi, I had the tranny filter and liquids changed too. This little adventure cost me about 415$ for those who are curious. I supposed it could have been worse but it hurt a bit. The best part is that I am back on the road.